Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Dental caries are one of the most prevalent chronic diseases. Worldwide 60 to 90 percent of school children and nearly 100 percent of adults experienced dental caries. The management of dental caries demands detection of carious lesions at early stages. The research of designing diagnostic tools in caries has been at peak for the last decade. This research aims to design an automated system to detect and score dental caries according to the International Caries Detection and Assessment System (ICDAS) guidelines using the optical images of the occlusal tooth surface. There have been numerous works that address the problem of caries detection by using new imaging technologies or advanced measurements. However, no such study has been done to detect and score caries with the use of optical images of the tooth surface. The aim of this dissertation is to develop image processing and machine learning algorithms to address the problem of detection and scoring the caries by the use of optical image of the tooth surface.

Cardiac injury is increased following ischemia-reperfusion. Mitochondria are the “effector organelles” that are damaged during ischemia (ISC) when there is no blood flow. Resumption of metabolism by damaged mitochondria during reperfusion (REP) results in increased cell injury. Current therapeutic interventions to pre-condition and post-condition the heart during ISC are ineffective during certain conditions like aging and diabetes due to defects in the signaling cascades. In contrast, mitochondrial-based strategies are effective in protecting the heart during ISC-REP. Hence direct therapeutic targeting of dysfunctional mitochondria will provide the potential to bypass the upstream signaling defects and intervene directly upon the effector organelle. Novel mitochondrial-targeted therapy relies on understanding the sites in the electron transport chain (ETC) that are damaged by ISC and produce cell-injury during REP. This project identifies a novel pathological role of cytochrome c in depleting cardiolipin during ischemia after which the mitochondria are in a defective condition that leads to additional cell death during reperfusion. During ischemia oxidants from complex III oxidize cytochrome c, forming a peroxidase, which causes oxidative damage and depletion of cardiolipin. Depletion of cardiolipin disrupts normal physiology and augments cell death. Identification of the innovative pathobiology during ISC-REP recognizes a novel therapeutic target, cytochrome c peroxidase, which can be a focal point for new therapeutic interventions to decrease cardiac injury. In order to maintain homeostatis, living organisms have the methionine sulfoxide reductase system, which reduce both free and protein bound Met(O) back to methionine (Met) in the presence of thioredoxin. Oxidized Trx is inactive and unable to bind to ASK1 thereby activating ASK1 and causing cell death via p38/JNK pathways thereby contributing to the pathogenesis of myocardial ISC-REP injury. In this study we have shown that inhibition of ASK1 protects the heart during REP via the modulation of mitochondria that sustained damage during ISC. The mitochondrial-based mechanism of cardioprotection with ASK1 inhibition enhanced the functional integrity of the inner mitochondrial membrane retaining cytochrome c thereby decreasing cell death. This therapeutic intervention is a key step to achieve the ultimate goal to improve clinical outcomes in patients that suffer an acute myocardial infarction.

Title of thesis: Influence of intra-abdominal pressure on the stability of the lumbar spine Definition of the problem: This thesis addresses the problem of the stabilization mechanism of the lumbar spine and the influence of intra-abdominal pressure on the stability of the lumbar spine. Objectives: The aim of my thesis is to locate, evaluate and process all available resources and to bring up the issue of IAP and its influence on the lumbar spine. The work should provide the widest possible insight into the problems of IAP effects on the stability of the lumbar spine, summarize differing opinions, and allow easier orientation in the isme. Method: The work is treated as a search, focusing on the processing and retrieval of literature concerning the issue. Studies included range from 1953 to present. To which I will use a variety of sources of literature, internet and consultation with the head of my thesis. Results: The increase in IAP, which is provided by a synchronous contraction of the diaphragm, pelvic floor muscles and m. transversus abdominis, can effectively stabilize the spine. But you can not determine with certainty whether this mechanism to support the stability of the lumbar spine is indeed used or the stability is provided by contraction of muscles, leading to an increase in IAP, and...

Studien utgår ifrån posthumanistiska teorier som ser på mänsklig och icke-mänsklig materia som agentiska aktörer. Studien undersöker vad som uppstår emellan yngre barn och appar i förskolan. Utifrån utvalda videosekvenser där ett- och tvååriga barn samhandlar med avancerade appar i en förskolepraktik analyseras sekvenserna utifrån posthumanistiska begrepp och ANT-analys. Resultatet belyser mycket täta, intensiva och komplexa möten där varje intra-aktion förändrar och transformerar de innefattande aktörerna i nätverk. Fokus ligger på kommunikativa relationer av transdisciplinära tillblivelseprocesser av barns och avancerade appars möten.

Orientador: Marcelo Tavella Navega / Coorientador: Marcos Renato de Assis / Banca: Marcos Eduardo Scheicher / Banca: Ana Elisa Zuliani Stroppa Marques / Banca: Paula Regina Mendes da Silva Serrão / Banca: Karina Gramani Say / Resumo: A articulação do joelho é frequentemente acometida por sinovite em pacientes com artrite reumatoide (AR). Esse processo inflamatório provoca um reflexo de inibição muscular artrogênica e consequente diminuição de força nos extensores de joelho, além de dor, edema e prejuízos funcionais. A infiltração intra-articular (IIA) com hexacetonide de triancinolona (HT) tem se mostrado eficaz no controle do acometimento articular em pacientes com AR. O objetivo geral do presente estudo foi analisar os efeitos da infiltração intra-articular em mulheres com AR de HT ou solução salina em parâmetros como força muscular de extensores de joelho, dor, edema, funcionalidade e amplitude de movimento. Vinte e uma mulheres com AR foram randomizadas aleatoriamente para receber 3ml de HT (GI) ou de solução salina (GC) no joelho, com avaliações feitas em 4 momentos: imediatamente antes a IIA, após 2, 6 e 12 semanas. Foram aplicados questionários para funcionalidade (WOMAC, Lequesne, HAQ), escala visual analógica para dor ao repouso e ao movimento, circumetria, teste de força de extensores de joelho, biofotogrametria para amplitude de movimento e os testes físicos Timed Up And Go (TUG) e Teste de Sentar e Levantar. Na análise estatística foi realizado teste de normalidade de Shapiro-Wilk, Teste de Levene para homogeneidade dos grupos, análise de variância (ANOVA) mista com medidas repetidas para comparação intra e inter grupos, correlação de Pearson e regressão linear com significância de P< 0,05. Fo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The knee joint is often affected by synovitis in rheumatoid arthritis (RA) patients. This inflammatory process causes a reflex of arthrogenic muscle inhibition and consequent decrease of strength in the knee extensors, pain, swelling and functional impairment. Intra-articular infiltration (IIA) with triamcinolone hexacetonide (HT) has been shown to be effective in controlling joint involvement in RA patients. The general objective of the present study was to analyze the effects of intraarticular infiltration in RA women's knee with HT or saline solution in parameters such as knee extensors muscle strength, pain, swelling, functionality and range of motion. Twenty-one RA women were randomly assigned to receive 3ml of TH (GI) or saline solution (GC) in the knee, with assessments made in 4 moments: immediately before the IIA, after 2, 6 and 12 weeks. Functional questionnaires (WOMAC, Lequesne, HAQ), visual analogue scale for pain, circummetry, knee extensor strength test, biophotogrammetry for range of motion and the physical test Timed Up And Go (TUG). Statistical analysis was performed using the Shapiro-Wilk normality test, Levene test for homogeneity of groups, mixed analysis of variance (ANOVA) with repeated measures for intra and inter group comparison, Pearson's correlation and linear regression with significance of P <0,05. Decreased pain at rest and movement, reduction of swelling and improvement of functionality in the group receiving the medication were observed, but t... (Complete abstract click electronic access below) / Doutor

Em dentes com lesão periapical, o tratamento endodôntico em duas sessões, com aplicação de curativo de demora, apresenta maior sucesso no combate à infecção intra e extrarradicular, proporcionando reparo dos tecidos apicais e periapicais. No entanto, o tratamento em sessão única vem sendo recomendado em função de reduzir custos e sessões de tratamento, apesar da sua comprovada ineficácia na erradicação dos micro-organismos e taxa de sucesso inferior. Diante da necessidade de reduzir o tempo clínico e favorecer a reparação tecidual, a aplicação de medicação com pasta à base de hidróxido de cálcio apenas na região apical e periapical, obtida por meio de seu extravasamento via canal radicular, seguida pela obturação na mesma sessão poderia constituir uma nova opção de tratamento. Com este objetivo, um total de 60 raízes de pré-molares de cão com rizogênese completa e lesões periapicais experimentalmente induzidas, foram aleatoriamente divididos em 3 grupos submetidos a diferentes protocolos de tratamento endodôntico: 1) novo protocolo em sessão única, com aplicação de pasta à base de hidróxido de cálcio na região apical e periapical antes da obturação; 2) tratamento convencional em duas sessões, com utilização de curativo de demora com pasta à base de hidróxido de cálcio durante 14 dias; 3) tratamento convencional em sessão única. Para avaliação da resposta tecidual, os dentes foram avaliados radiograficamente e histopatologicamente, 120 dias após o tratamento endodôntico com a eutanásia dos animais. Os espécimes foram processados histotecnicamente, corados com HE e avaliados com microscopia de luz convencional e de fluorescência. Os resultados obtidos foram analisados estatisticamente utilizando os testes qui-quadrado, Fisher, Anova e pós teste de Tukey, com nível de significância de 5% em todos os testes. De acordo com os resultados radiográficos, os dentes tratados com o novo protocolo apresentaram redução na área radiolúcida periapical semelhante aos dentes tratados em duas sessões (p<0,05) e ambos foram superiores ao tratamento em sessão única (p<0,001). Os resultados histopatológicos mostraram que a realização do novo protocolo proporcionou a reparação das estruturas periapicais e apicais em evolução, com presença suave de fibras colágenas jovens, poucos vasos sanguíneos neoformados, infiltrado inflamatório suave a moderado, deposição de cemento celular ou reinserção de fibras colágenas em lacunas de reabsorção paralisadas e selamento apical completo em 18,2% dos casos. Os dentes tratados em duas sessões apresentaram estágio de reparação mais avançado, com a mesma espessura do espaço do ligamento periodontal, porém com presença de fibras colágenas mais maduras, mais vasos sanguíneos jovens, infiltrado inflamatório suave, deposição de cemento celular em lacunas de reabsorção paralisadas e processo de selamento apical completo em 30,8% dos casos. Nos dentes tratados em sessão única, observou-se persistência da lesão periapical com presença de infiltrado inflamatório moderado a severo, presença de reabsorção ativa dos tecidos mineralizados, ligamento periodontal aumentado e ausência de selamento apical em 100% dos casos, sendo estatisticamente diferente dos grupos anteriores em todos parâmetros avaliados (p<0,001). Foi possível concluir que o novo protocolo de tratamento em única sessão promoveu a reparação tecidual, porém em estágio menos avançado que o tratamento em duas sessões com utilização de curativo de demora / In apical periodontitis, two-session endodontic treatment using intracanal medication between appointments presents a higher success rate at intra and extra radicular disinfection giving a better apical and periapical tissues repair. Meanwhile, one-session treatment has been highly recommended due to fewer operative time and expenses, even having its proven inefficacy in root canal system cleansing and lower success rate in apical and periapical tissues repair after endodontic treatment. To reduce operative sessions and costs while promoting tissue repair and patients comfort, we proposed a novel protocol in endodontic treatment of apical periodontitis with extravasation of a CH-based paste into periapical region and obturation performed in a single session. A total of 60 mature dogs premolar teeth with experimentally induced periapical lesions were randomly classified into 3 groups: 1) Novel protocol with extravasation of CH-based paste into apical and periapical region and obturation performed in a single session, 2) Two-session treatment with CH-based intracanal medication in 14 days-interval sessions and 3) Single-session treatment. Radiographs were taken at day 0 and day 120. After 120 days, animals were killed, maxillae and mandibles were histotechnically processed and stained with HE and analyzed under conventional and fluorescent microscopy. Descriptive, semi quantitative and quantitative histopathological of histopathological parameters was performed. Results were statistically analyzed using chi square test, Fisher test, Kruskal-Wallis test, Dunns post-test, Anova one-way and Tukeys test, with a 5% level of significance. According to radiographic analysis, teeth treated with the novel protocol had a percent rate reduction similar to teeth with a two-session treatment (p<0,05), and both groups were superior to single-session group. Histopathological analysis results showed that performing endodontic treatment using the novel protocol provided repair in process of the apical and periapical structures, with few young collagen fibers, few neoformed blood vessels, mild to moderate inflammatory infiltrate, cellular cement deposition or collagen fibers reinsertion at inactive resorption lacunae and complete apical sealing in 18,2% of teeth. Teeth treated in two sessions had a more advanced repair with a similar periodontal ligament thickness, however, with more mature collagen fibers, neoformed blood vessels, mild inflammatory infiltrate, cellular cement deposition at inactive resorption lacunae and complete apical sealing in 30,8% of specimens. In teeth treated in a single session, we observed persistence of the periapical lesion with a moderate to severe inflammatory infiltrate, active resorption of the mineralized tissues, increased periodontal ligament thickness and absence of apical sealing in 100% of specimens, being statistically different to the other groups in all evaluated parameters (p<0,001). We conclude that the proposed novel protocol promoted an early repair of apical and periapical tissues, yet, less developed than two-session treatment with utilization of intracanal medicament in between sessions

A research report submitted to the School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Dentistry in the branch of Prosthodontics Johannesburg, 2017 / Purpose: To perform a comparative analysis of the accuracy of intra-oral and extra-oral digital scanners when used for the milling of a long-span implant supported superstructure framework. Method: Three intra-oral and three extra-oral scanners were used to measure a master model containing five implant analogues. The three-dimension positions of the implant analogues were measured with a coordinate measuring machine. The digital data from the scanners were used to mill the implant positions in aluminium blanks from a single milling device. These implant positions were measured at the same points as the master model. The three-dimensional differences were calculated to provide a measure of the most accurate frameworks. Results: For the intra-oral scanners, the further the measurement between points, the greater the standard deviation (the poorer the precision) and the poorer the mean accuracy. However, these were clinically acceptable over short distances. For the extra-oral scanners, there was no correlation between the length of the measured distances and the accuracy of the produced framework. All the extra-oral scanners were clinically acceptable for complete-arch prostheses. Conclusions: Noting the limitations of this study and the use of a milling centre to mill the frameworks, for the intra-oral scanners, the 3Shape Trios® (3Shape, Copenhagen, Denmark) can be used for measurements up to 21,5mm and the Sirona CEREC OmniCam (Sirona Dental Systems, Inc., Bensheim, Germany) can be used for measurements up to 34mm. The extra-oral scanners used in this study can be used for complete-arch implant prosthetics. The accuracy of these is relative to the model or impression created. Steps should therefore be made to ensure the accuracy of the model such as the use of a verification jig / MT2017

The main goal of this research is to investigate whether foreign exchange transacting costs are an impediment to intra-regional trading within the Southern African Development Community SADC region. The research question posed has been whether foreign exchange trading costs affect the amount of intra-regional trading within the SADC region. Once the impediments relating to regional trading have been broken down and the cost effect on Small, Medium and Micro Enterprises SMMEs is established, then possible solutions are proposed. The research discovers that the cost of foreign exchange has an impact on intra-regional trading, but it is not the main hindrance to intra-regional trading in the SADC. It also discovers that the settlement risk of a foreign exchange transaction in the region has not yet been addressed to the same or similar extent as in the developed world. The extent of trading partners’ currency volatility is a function of the amount of trade between those trading partners. The SADC countries’ currency pairs volatility can be reduced by increased trade. Having said that, businesses need to plan and high levels of volatility tend to be disruptive. This is now the area where it is suggested that central banks within the region should actively participate in foreign exchange markets. Central banks should be the facilitator or price-maker of last resort in cases of lack of liquidity of local or foreign currencies. The research suggests that they should play a role in ensuring or reducing the amount of rapid currency spikes that lead to disorderly markets. The research also discovers that SMMEs are a core part of the economies of developing countries, and therefore a serious look at this sector of the economy is suggested. Mobile communication networks, like cell phones, are the current accessible and preferred communications tool among the geographical regions and areas that are hard to reach. Cell phones have also doubled as a form of payment among rural, African countries. The research suggests leeching on the current cell phone iii banking platforms to enable better foreign exchange reach to SMMEs and the general public. It suggests interlinking relationships between banks and cell phone networks, where the cell phone companies facilitate the accessibility and the banks’ liquidity. The report takes cognisance of the fact that, inasmuch as the countries in SADC are geographically close to each other, their political, economic and social dynamics can be wildly different. This would therefore mean that the proposed solutions are not necessarily a one-size-fits-all, but could be adjusted and tweaked to suit individual country dynamics.

In what ways do companies within an industry converge? We address this by combining theory on competitive strategy and supply chain strategy to understand how companies can be differentiated in these dimensions. As competitive strategies are affected by internal and external factors, these affect strategy design and resource management of a company in order to remain competitive. Convergence occurs when an industry matures, and several regulatory or non-regulatory norms arise that firms move toward and, in the process, become more similar. Through developing a framework that addresses intra-industry convergence and taking the case of the European airline industry, we aim to demonstrate the application of using competitive strategy and supply chain strategy analyses to analyze and evaluate intra-industry convergence through a standardized model.